Engine build on the brain

[abodyjim]

No way I'm using a factory o/d unit.

Finally,if considering an overdrive, absolutely forget about the Mopar box. The rpm drops between gears, at speed are waaaay too wide for a combo like yours. I tried it with two cams; the smaller was a 270/276/110 cam, and the slightly larger 276/286/110; and nearly every gear from 2.76 to 4.88, and it was just terrible; there was no way to keep the engine on the power band of a performance 110 cam. I left it in the smaller combo for about a year , but that was that.
The ratios are 3.09-1.67-1.00-.73od and the splits are 54%-60% and 73%. meaning;
that at whatever rpm you shift out of, the rpm will fall to those %s. So shifting at say 6000rpm, the Rs will fall to 3240 on the 1-2 and to 3600 on the 2-3. With 4.30s and 30s, the 1-2 would be at 47mph. At the drop to 3240 your engine better have a chitload of torque, to get back up on the cam. The 2-3 shift would come at 6000/75 mph, and your street run is already done...... so at this point nobody cares about the 2-3 drop. But at the track, your Rs would fall to 3600 on the 2-3 shift... so again, yur a solid 800rpm off the powerband. IMO, this really sucked. So I was done with it. Not to mention I blew three of them up, trying to make it work.
I hate to sound cliched but trust me, you don't want that A833 od box.
And 4.30s are probably not nearly enough rear gear with the 30s.

 

[rumblefish360]

Wooooo, missed this quick moving thread!

Im liking it so far.

 

[Wyrmrider]

abody
edit-- typed this on a minipad that plus dyslexia and no wonder it comes out garbled
try everything you can to get the quench/ squish below .050 or over 100
if you said what motor you are working on I missed it
refresh me
and if you have long rods say so

did you mean
no way- I'm using the factory od
on fkn wy Im usig the factory od?

 

[AJ/FormS]

criminy, this is like extracting hen's teeth.

 

[rumblefish360]

Say what? Wyrm! Proof read! Your posts are getting out there, cryptic & slightly confusing.

abody
try everything you can to get the quench/ squish below .050 or over 10

Below .050 or 10? Say what?

and if long rods say so

Say what again?

 

[nm9stheham]

So if I'm bench racing this correct using my parts I could set the pistons down .020 in the hole with .054 head gasket a revised Isa of 68.5 and put me on the edge of pump gas
Am I on the right track?

View attachment 1715462317

Yes, you are on the right track and working the numbers the right way. So that is very good.

I've run 8.3 DCR on iron heads (351C) WITH quench and it was fine on 93 pump premium ('back-in-the-day' gas). If I went from 1000' elevation to sea level I would see the engine get 'touchey' as to octane. And I'd have to limit timing... it did not make me at all unhappy to do that, as I am not drag racing.

I doubt that I ever tuned the thing nearly like YR and AJ have done. I'm actually a bit lazy on that LOL. And I can't say that YR is wrong to de-empahsize the quench factor... I just am not comfortable with NOT doing quench myself; all my builds in this range of DCR have had it and have all been successful in pushing DCR without detonation.

But heck... you have open chamber heads... no quench anyway unless you get some of the quench-dome types from KB or ICON.

Now if you are willing to do like you are thinking and run some higher octane for those times you want to create havoc on the streets, and then detune for pump gas on trips, that works.

Mind sharing the other input numbers that go into your computation of static CR? Piston type and chamber cc's....

 

[abodyjim]

Not gonna pretend like I know what I'm talkin about that's why my original goal was to try and educate myself on static, dynamic and camshafts so I understand the advice you all give and apply it to my junk. I've put stuff together with no knowledge of the stuff mentioned above and it shows. So I did what alot of people do and try to copy others and hope for similar results.
Here's the list of what I have and intended goal.
Goal/600hp or close-not chasing it but believe that the parts should get it somewhere close.
Intended use/dragweek with more than a weeks life expectancy would be the best explanation.
The work on the heads and the camshaft was done and picked with the goals in mind mentioned above.
Heads/ 810 castings I believe/ w2 open chamber and they are iron. 68cc combustion chambers. They are also the econo version so I'm limited to .650 valve lift max. I choose these heads because I already owned them. I also have the accompanying parts to make them work.
Headers/ w2 tti
T&D 1.5 roller rockers
Intake/ Victor w2 also ported by the same guy that did the heads
Head flow numbers listed below
Block is a 360 no machining done yet
Stroker kit already purchased
4" Scat forged crank
Scat H beam 6.123 rods
Icon forged flat top pistons, (-5cc)part number ic-744-060 /yes .060 over the block was already .030 and had some wall damage. The head guy said the bigger bore would actually benefit me in uncovering the valves.
Camshaft/already purchased and is what bullet picked/solid roller
Other points of interest are fuel and ignition. It will be efi and control the timing.
I have the crank trigger, cam sensor, ls coils. I was gonna use a Holley dominator ecu but decided to use it on another project. So I still need some things there but I think you can see the direction its going.
As for the transmission I have a 4 speed and scatter sheild that came out of the car and will be reused. A factory o/d is not even a consideration nor is a automatic. A upgrade to a tremic or something maybe after this thing moves on its own.
Rearend is 8.75 and what I meant with the any gear is I have 3.23,55,91 4.56 5.38 and if none of those work then I will get what I need.
The car is a 72 duster with the normal chassis stiffening and full tubs. Rear is narrowed with ladder bars and so on.
Rear tires are 295 65 15 drag radials but looking at going 315 60 15 which knocks the height down to 29.9 feom 30.1 so no real difference.
Also Kansas elevation is around 890 according to my phone.
I have full confidence that the head guy and bullet did what was asked in making hp. Race gas for full potential does not bother me. I was trying to figure if I could get by on pump premium to go from A to B. That was the reasoning behind seeing if I can make it work with these pistons or would I be better off going to a dish piston.
So.....let me know what you all think

 

[abodyjim]

Here's how I got to my previous post, I adjusted deck height and used a thicker head gasket to drop the static comp. Then using a adjusted number for the Ica 68.5 gave me the numbers here

 

[yellow rose]

Here's how I got to my previous post, I adjusted deck height and used a thicker head gasket to drop the static comp. Then using a adjusted number for the Ica 68.5 gave me the numbers here

View attachment 1715462810

You can EASILY run 11:1 with what you are doing.

If you haven't already, contact Mike at B3 reading engines and get his geometry correction kit.

The heads flow enough to make 600 HP if you get the CR up.

Now, after I've run my mouth, I need to take a closer look at your cam numbers.

BRB

 

[yellow rose]

I would use 11.5:1 CR and put the cam in at 108 and not 106. That will open the exhaust a touch later and close the intake a touch later.

 

[abodyjim]

If I use a fel pro 1008 head gasket .039/4.18 I get a compression of 11.38. Recalculate for 108 install and I get a dynamic of 8.71 and cranking pressure of 177 if I'm doing it right. This is where I'm getting confused, these numbers are high for what's considered safe if I understand it right. What kind of numbers should I be looking for to meet my goal and intended use

 

[yellow rose]

If I use a fel pro 1008 head gasket .039/4.18 I get a compression of 11.38. Recalculate for 108 install and I get a dynamic of 8.71 and cranking pressure of 177 if I'm doing it right. This is where I'm getting confused, these numbers are high for what's considered safe if I understand it right. What kind of numbers should I be looking for to meet my goal and intended use

With those numbers you are about right where I'm at on pump gas.

Just make sure you do the little things...like using an intake without a heat crossover (I think you are using EFI and if it's port EFI I still would not heat the air in the intake) get your timing curve in shape and get your cooling system where you can maintain ~170 degree coolant temp (can be 160ish if you done need a heater but I need one so I keep mine at 170) and get the correct heat range plug and you'll be golden.

I've been ignoring all those numbers for decades. Guys just waste power not getting the CR up where it should be.

 

[abodyjim]

Perfect, I'm on track
Thanks

With those numbers you are about right where I'm at on pump gas.

Just make sure you do the little things...like using an intake without a heat crossover (I think you are using EFI and if it's port EFI I still would not heat the air in the intake) get your timing curve in shape and get your cooling system where you can maintain ~170 degree coolant temp (can be 160ish if you done need a heater but I need one so I keep mine at 170) and get the correct heat range plug and you'll be golden.

I've been ignoring all those numbers for decades. Guys just waste power not getting the CR up where it should be.

 

[nm9stheham]

Hey OP, Is the 68 cc just a number you got somewhere for the chamber size, or were the chambers all measured and equalized to that cc number in the porting process?

I just ran your numbers. With the Icon 744's and standard LA deck height and rods, the piston tops end up at .012" in the hole, not quite zero-decked. Going with the 68 cc chamber size, and the Felpro 8553PT gasket at .051" thick, SCR is 10.6. For the Felpro 1008 at .039" thick, I get 10.9 SCR. Both gaskets have a bore size of 4.18" so there is more volume to account for if you have not done so. And I always add at least 1 cc to the eyebrow volume to account for crevice space down to the top ring.

I get 8.5 DCR for seal level for the thinner head gasket, and 8.3 DCR for the thicker one at sea level, using 68.5 for the ICA. At your elevation, both numbers are going to be a bit lower.

So you appear to be doing things right with the caclulators, but it is small details in dimensions that make a difference. (BTW, your posts of you input numbers don't show the entry data... just the final output data.)

As for acceptable DCR, 8.0 is a pretty common number to work to for a good build and paying attention to tune for pump premium. 91 Octane seems a bit touchier based on some reports here. I am fine there (even with my lazy tuning habits!) and have been up in the 8.3 range, as mentioned earlier. Now AJ and YR have managed to really work it up higher with more attention to details and fine tuning.

So no way I would go to dish tops.... the next bus stop on that road is more than a point lower in SCR and DCR.

OBTW, have the block sonic tested before that .060" overbore.

 

[nm9stheham]

Just make sure you do the little things...like using an intake without a heat crossover (I think you are using EFI and if it's port EFI I still would not heat the air in the intake) get your timing curve in shape and get your cooling system where you can maintain ~170 degree coolant temp (can be 160ish if you done need a heater but I need one so I keep mine at 170) and get the correct heat range plug and you'll be golden.

Hey YR, are you measuring coolant temp at the normal SBM temp sensor point?

And the OP needs to know that with his HP levels, keeping the temps down to those levels is not just a matter of popping in a different t-stat. Needs a definite upgrade to the cooling system and paying attention to the details there, versus a stock system or a cheapo chinese rad.

 

[yellow rose]

Hey YR, are you measuring coolant temp at the normal SBM temp sensor point?

And the OP needs to know that with his HP levels, keeping the temps down to those levels is not just a matter of popping in a different t-stat. Needs a definite upgrade to the cooling system and paying attention to the details there, versus a stock system or a cheapo chinese rad.

Yes. And I did a ton of research before I started my engine build.

I should have enough left over in the cooling side of things to do the next engine and keep it cool.

The goal is 12:1 pump gas and 600 HP.

My wife says I need help.

 

[rumblefish360]

Yes. And I did a ton of research before I started my engine build.

I should have enough left over in the cooling side of things to do the next engine and keep it cool.

The goal is 12:1 pump gas and 600 HP.

My wife says I need help.

I don’t see a problem here. So long the timing events and overall pressures are right.....

 

[Wyrmrider]

I fixed it Rob
I was trying to say he needs to stay away from .060 to .100 open space between piston and head - he has no quench
check out Icon 982,983,984 depending on head ccs, gasket and how much compression he wants\he can get some quench
I was in on the design of the B versions of these pistons with United chief engineer John Erb (retired) many years ago
we had lots of miles and dyno time on the development with both gas and propane (who was paying the bills)
hell have to do a mock up to get it dialed in but I recommend doing that anyway
do this and low end and mid range can be picked up
less fussy on gas and timing
now if he is always going to be running above peak torque (trailer queen) then he can make open chambers and FT work
top end hp might even be a little more -very little

 

[abodyjim]

Nm9 68 is what I got from the head guy. The heads were surfaced and work done to the bowls. I can't guarantee they are all equal
Thanks for running the numbers. I'll remember to post the inputs along with what I'm getting. I was using 0.00 deck height because I didn't what it would be or how to figure it.
I haven't put a lot of time into the cooling side but I did eead some write ups on a Mercedes radiator and fan swap. I might be wrong on the Mercedes part but looked like something that would work.
While we are talking cooling it was recommended to do a partial block fill to help keep it together. My concern there is the partial fill will hurt me in cooling
Wyrm I took a quick glance at those pistons and they all drop compression. I'm gonna go back snd try to figure out what you're saying

 

[yellow rose]

Nm9 68 is what I got from the head guy. The heads were surfaced and work done to the bowls. I can't guarantee they are all equal
Thanks for running the numbers. I'll remember to post the inputs along with what I'm getting. I was using 0.00 deck height because I didn't what it would be or how to figure it.
I haven't put a lot of time into the cooling side but I did eead some write ups on a Mercedes radiator and fan swap. I might be wrong on the Mercedes part but looked like something that would work.
While we are talking cooling it was recommended to do a partial block fill to help keep it together. My concern there is the partial fill will hurt me in cooling
Wyrm I took a quick glance at those pistons and they all drop compression. I'm gonna go back snd try to figure out what you're saying

Buy a radiator that fits your car. I'd look at Cold Case. They are a sponsor here on FABO. You want the biggest 2 core radiator, with the cores as big as you can get.

Over drive the water pump. Use a Stewart Components thermostat and a Milodon high flow or Flowkooler water pump.

 

[nm9stheham]

Buy a radiator that fits your car. I'd look at Cold Case. They are a sponsor here on FABO. You want the biggest 2 core radiator, with the cores as big as you can get.

Over drive the water pump. Use a Stewart Components thermostat and a Milodon high flow or Flowkooler water pump.

Yes yes yes ! This is the only way to get those temps to stay down. Especially on the rad. It'll cost a few $$.

This is good stuff. Tnx YR

Nm9 68 is what I got from the head guy. The heads were surfaced and work done to the bowls. I can't guarantee they are all equal
Thanks for running the numbers. I'll remember to post the inputs along with what I'm getting. I was using 0.00 deck height because I didn't what it would be or how to figure it.

Very good abjim. I figured we were just off on some of the detailed inputs.... your numbers were just coming in too close for you to be making any fundamental errors with the calculators. And the 68 cc number sounds like it is a good solid number to work with.

and if you have long rods say so
did you mean
no way- I'm using the factory od
[OR IS IT]
no fkn wy [that] Im [gonna] use the factory rod?

LOL. Interpretation included above.
I am pretty sure abjim is using stock length rods (6.123"). Please confirm that is the case, abjim.

 

[abodyjim]

Yes its a standard rod 6.123. Thank's for all the help guys
YR thanks for the tips on the cooling system